Model of a putative transcription network of gene, protein and hormonal stimulus of follicle development [6, 13, 14]. The process starts with the formation of germ cells and continues with the development of oogonia and oocytes. Several factors are involved in the PGC formation, oogonial (Oct-4), and oocyte development (Figα, Nobox, etc.). Specific oocyte differentiation factors in preantral follicular stages are, YP30, ZP1-3 and those of cortical granulosa content: DF1,9 ovoperoxidase (Opo), proteoliasin (Pln), and rendivin (Rdv). PMFs: Primordial follicles, PF: primary follicle, SF: secondary follicle, IGF (family of the insulin-like growth factors). With permission from Song and Wessel [14].
